Shimano M5100 Deore 11 Sp Boost Double ChainsetReady for the steep stuff, the fast stuff, as well as the fun stuff, this 11 speed MTB crankset gives you powerful acceleration and smooth shifting performance. It features a hard-wearing forged alloy crank arm construction, which allows it to handle all the abuse that's associated with all-day epics in the mountains. Shimano has also kitted out this model with a HollowTech II integrated bottom bracket design for increased stiffness, efficiency and added durability.Features: Crank Arm Material: Forged Alloy Use: MTB Speed: 2x11 speed Number of Chainrings: 2 Chainrings Included: Yes Design: 2-piece Chainline: 51.8mm Chainring BCD: For use with 148 mm O.L.D. frames 4 Arm or 5 Arm: 4 arm Chainring Size: 36/26T Is BB Included: HollowTech II integrated bottom bracketPart Numbers: 170mm: FCM5100BC66; 175mm: FCM5100BE66Technologies: HollowTech II: HollowTech II integrated bottom bracket design uses a wide bearing placement with a large axle diameter for increased stiffness, efficiency and added durability. Forged Crank Arms: Forged crank arms rigid whilst being incredibly strong and durable.A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.
Shimano M6130 Deore 12Sp Super Boost ChainsetEngineered for maximum performance on every MTB adventure, this single Boost crankset gives you fast acceleration and control on the toughest of rides. It features a robust forged alloy crank arm construction, which makes it more than capable of withstanding all the abuse that's associated with all-day epics in the mountains. Shimano has also made this version compatible with HollowTech II integrated bottom brackets for increased stiffness, efficiency and added durability.Please note: A bottom bracket is available separately.Features: Crank Arm Material: Forged Alloy Chainring Material: Lightweight Aluminium Use: MTB Speed: 12 speed Number of Chainrings: 1 Chainring Included: Yes Chainring Tooth Count: Multiple options available Crank Arm Length: Multiple options available Axle Diameter: Boost Chainline: 56.5mm Chainring BCD: For use with 157mm O.L.D. frames 5 Arm or 4 Arm: 4 arm Chainring Mount: Direct mount Design: 2-piece Dyna-Sys Compatible: Yes Compatibility: 12 speed Dyna-Sys MTB HG-X transmissions Is BB Included: No Bottom Bracket Compatibility: HollowTech II integrated bottom bracket Part Numbers: 30T 170mm: FCM6130C0; 30T 175mm: FCM6130E0; 32T 170mm: FCM6130C2; 32T 175mm: FCM6130E2Technologies: HollowTech II: HollowTech II integrated bottom bracket design uses a wide bearing placement with a large axle diameter for increased stiffness, efficiency and added durability. A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.
Shimano M6130 Deore 12Sp Super Boost ChainsetEngineered for maximum performance on every MTB adventure, this single Boost crankset gives you fast acceleration and control on the toughest of rides. It features a robust forged alloy crank arm construction, which makes it more than capable of withstanding all the abuse that's associated with all-day epics in the mountains. Shimano has also made this version compatible with HollowTech II integrated bottom brackets for increased stiffness, efficiency and added durability.Please note: A bottom bracket is available separately.Features: Crank Arm Material: Forged Alloy Chainring Material: Lightweight Aluminium Use: MTB Speed: 12 speed Number of Chainrings: 1 Chainring Included: Yes Chainring Tooth Count: Multiple options available Crank Arm Length: Multiple options available Axle Diameter: Boost Chainline: 56.5mm Chainring BCD: For use with 157mm O.L.D. frames 5 Arm or 4 Arm: 4 arm Chainring Mount: Direct mount Design: 2-piece Dyna-Sys Compatible: Yes Compatibility: 12 speed Dyna-Sys MTB HG-X transmissions Is BB Included: No Bottom Bracket Compatibility: HollowTech II integrated bottom bracket Part Numbers: 30T 170mm: FCM6130C0; 30T 175mm: FCM6130E0; 32T 170mm: FCM6130C2; 32T 175mm: FCM6130E2Technologies: HollowTech II: HollowTech II integrated bottom bracket design uses a wide bearing placement with a large axle diameter for increased stiffness, efficiency and added durability. A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.
Shimano MT610 12 Speed Boost Double ChainsetReady for fast and fun MTB rides, this 12 speed MTB crankset gives you powerful acceleration and smooth shifting performance. It features a rock-solid forged alloy crank arm construction, which enables it to withstand all the intensity that's associated with all-day epics in the mountains. Shimano has also kitted out this model with a HollowTech II integrated bottom bracket design for increased stiffness, efficiency and added durability.Features: Crank Arm Material: Forged Alloy Use: MTB Speed: 2x12 speed Number of Chainrings: 2 Chainrings Included: Yes Design: 2-piece Chainline: 51.8mm Chainring BCD: For use with 142/148mm O.L.D. frames 4 Arm or 5 Arm: 4 arm Chainring Size: 36/26T Chainring Mount: Direct mount Chain Compatiblity: For use with 12 speed HG MTB chains only Is BB Included: HollowTech II integrated bottom bracketPart Numbers: 170mm: FCMT610BC66; 175mm: FCMT610BE66Technologies: HollowTech II: HollowTech II integrated bottom bracket design uses a wide bearing placement with a large axle diameter for increased stiffness, efficiency and added durability. Forged Crank Arms: Forged crank arms rigid whilst being incredibly strong and durable.A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.
Shimano M5100 Deore 11 Speed Double ChainsetEngineered for maximum performance on every MTB adventure, this double crankset delivers fast acceleration and smooth shifting operation on the toughest of rides. It features a forged alloy crank arm construction, which makes it perfect at handling all the abuse that's associated with all-day epics in the mountains. Shimano has also equipped it with a HollowTech II integrated bottom bracket for increased stiffness, efficiency and added durability.Features: Crank Arm Material: Forged Alloy Use: MTB Speed: 11 speed Number of Chainrings: 2 Chainrings Included: Yes Crank Arm Length: Multiple options available Chainline: 48.8mm Chainring BCD: For use with 135/142mm O.L.D. frames Chainring Tooth Count: 36/26T 5 Arm or 4 Arm: 4 arm Design: 2-piece Compatibility: 11 speed MTB drivetrains Is BB Included: HollowTech II integrated bottom bracketPart Numbers: 175mm: FCM5100E66; 170mm: FCM5100C66Technologies: HollowTech II: HollowTech II integrated bottom bracket design uses a wide bearing placement with a large axle diameter for increased stiffness, efficiency and added durability. SG-X Chainring: SG-X chainring with patented spike pins give smooth and fast gear shifts under load. A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.
Shimano Claris R2000 3x8 Speed ChainsetThis versatile 8 speed crankset offers easy to operate, precise and light-action shifting performance on your road bike. Whether you're commuting to work or planning a tour across the countryside, this reliable component uses a cascaded design that's taken from Shimano's high-end models to deliver fast and smooth operation on every ride. Coming equipped with a hard-wearing crank arm construction and a robust steel chainring, this chainset ensures that you get powered up to speed in seconds. Compatible with Shimano 8 speed HyperGlide chains, this version's sprockets also provide improved and highly efficient chain control when shifting.Features:Crank Arm Material: AluminiumChainring Material: SteelUse: Road, Fitness and TouringSpeed: 8 speedSeries: Claris R2000Number of Chainrings: 3Tooth Count: 50, 39 and 30TCrank Arm Length: Multiple options available to selectNumber of Gear Arms: 4 armBCD: 110/74mmType: 2-piece designBB Shell Width: 70mmBottom Bracket Included: NoChainline: 45mmChain Guard: Sold SeparatelyRecommended Bottom Brackets: Pressfit: BB-RS500-PB; Threaded (Normal): BB-RS500Q-Factor: 158.8mmRecommended Chain: Shimano 8 speed HyperGlide (HG)Part Numbers: 175mm: FCR2030E090; 170mm: FCR2030C090A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.
Shimano Sora R3030 9 Speed Triple ChainsetAll set for taking you from A to B on your road bike, this 3x9 speed crankset uses a high-end 4-arm design and compact 50-39-30T chainrings. It features a tough aluminium crank arm material with a steel axle, making it ideal at handling the increased pressure from fitness riding and longer journeys. Shimano has also equipped this version with its renowned Hyperglide sprockets that incorporate specially positioned shift ramps and tooth profiles for improved chain control during shifting. This results in fast and responsive indexed shifting as you travel from the smooth city pavement to the countryside. One final highlight is this model's 2-piece crank design that offers increased rigidity and less weight.Features:Crank Arm Material: AluminiumCrank Axle Material: SteelChainring Material: Large: Aluminium; Middle: Steel and Small: SteelUse: Road, FitnessUse: Road, FitnessSpeed: 9 speedNumber of Chainrings: 3Series: SoraBB Shell Width: 70mmBB Included: No2-piece Construction: YesChainline: 43.5mmChain Ring Combination: 50, 39 and 30TCompatibile BB Type: OutboardCompatible Chain: HG 9 speedCrank Arm Length: Multiple options available to selectGear Arms: 4Chain Guard / Bash Guard: Sold separatelyBCD: 110/74mmRecommended Bottom Bracket: Pressfit: BB-RS500-PB; Threaded (Normal): BB-RS500Q-Factor: 158.8mmPart Numbers: 170mm: FCR3030C090; 165mm: FCR3030A090 and 175mm: FCR3030E090Weight: 1180g (without bottom bracket)Technologies:2-Piece Crankset: Integrated crank arm and bottom bracket. Increased rigidity with less weight. Wider bearing positioning. Rigidity is enhanced and pedaling force is efficiently transmitted. Precision Bearings. Low maintenance and simplified installationHG HyperGlide: The distinctively designed HYPERGLIDE sprockets incorporate specially positioned shift ramps and tooth profiles for improved chain control during shifting. Fast and responsive indexed shifting is the result. The HG cassette sprocket, which was developed for the MTB 10-speed system, underwent comprehensive optimization to achieve super-highly efficient shifting.A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.
Shimano Dura-Ace R9200 12 Speed ChainsetThe Dura-Ace R9200 12 Speed Chainset from Shimano provides the optimum balance of strength and rigidity at a low weight. Shimano's Hollowtech II and Hollowglide technologies provide outstanding power transfer and smooth gear shifts while it's engineered to excel specifically with the Shimano 12-Speed road groupset systems.The Dura-Ace FC-R9200 chainset is the driving force at the heart of the bicycle. This chainset ensures that no portion of your pedal stroke is wasted. With hollow arms and chainrings, weight is kept to a minimum but stiffness and shifting precision is maximized.Hollowtech II Technology for World-Class Strength at a Low WeightThe Dura-Ace FC-R9200 crank performs two vital functions: transferring your pedalling effort into the drivetrain and ensuring the fastest, most precise front shifting available. With Hollowtech II crank arms to ensure lightweight and Shimano's class-leading chainring designs, the FC-R9200 won't let you down. And the FC-R9200 12 Speed Chainset is offered in even shorter crank arm lengths to ensure there are options to fit any rider.Hollowglide Chainring TechnologyHollow technology on the outer chainring. The Hollowglide construction ensures high rigidity while its hollow structure cuts down on weight yet maintains strength. This provides better power transfer and quicker and more precise front shifting performance.Hollowtech II Forged Crank ArmsA lightweight crankset not only reduces the bike's weight but decreases rotating mass to aid in acceleration. The challenge is to reduce the weight of the crank without reducing its strength and rigidity.Shimano's advanced forging technology has solved the problem through the HOLLOWTECH crank. Just like high-quality frame tubing, a hollow crank arm can provide amazing strength and rigidity at very lightweight.The Best Balance of Stiffness, Strength and WeightThe concept of Hollowtech II technology is focused on producing a superior crankset that will maximize a rider's power transfer. The rigidity of the crankset ensures pedalling efficiency while its low weight, a key element of the crankset, aids in cycling longer distances over which the rider needs to pedal more. Naturally, Shimano strove for the optimum balance between the conflicting needs of stiffness while producing a lightweight crank.The addition of Hollowtech II technology integrates the bottom bracket axle with the right crankarm for more stiffness and weight savings to achieve a high-dimensional balance. Its outboard bottom bracket bearing system provides better weight distribution and more pedalling stability, allowing for more efficient power transfer.The Shimano Dura-Ace R9200 12 Speed Chainset has been developed by pursuing the optimum balance of stiffness and rotating performance in a lightweight and beautiful crankset design.Features: Series: Dura-Ace R9200 Series Optimal balance of stiffness, strength, weight and rotational performance Hollowglide structure cuts weight yet maintains strength for better power transfer and quicker, more precise front shifting New 54-40T option to realize the most efficient drivetrain Hollowtech II crank arms for strength at a low weight Recommended Bottom Bracket: Press-Fit: SM-BB92-41B; Threaded: BB-R9100 Q-Factor: 148mm Drivetrain Rear Speeds: 12-Speed Chainline: 44.5mm Weight: 714g (54-40T); 692g (52-36T); 685g (50-34T)A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.
Shimano Dura-Ace R9200 12 Speed ChainsetThe Dura-Ace R9200 12 Speed Chainset from Shimano provides the optimum balance of strength and rigidity at a low weight. Shimano's Hollowtech II and Hollowglide technologies provide outstanding power transfer and smooth gear shifts while it's engineered to excel specifically with the Shimano 12-Speed road groupset systems.The Dura-Ace FC-R9200 chainset is the driving force at the heart of the bicycle. This chainset ensures that no portion of your pedal stroke is wasted. With hollow arms and chainrings, weight is kept to a minimum but stiffness and shifting precision is maximized.Hollowtech II Technology for World-Class Strength at a Low WeightThe Dura-Ace FC-R9200 crank performs two vital functions: transferring your pedalling effort into the drivetrain and ensuring the fastest, most precise front shifting available. With Hollowtech II crank arms to ensure lightweight and Shimano's class-leading chainring designs, the FC-R9200 won't let you down. And the FC-R9200 12 Speed Chainset is offered in even shorter crank arm lengths to ensure there are options to fit any rider.Hollowglide Chainring TechnologyHollow technology on the outer chainring. The Hollowglide construction ensures high rigidity while its hollow structure cuts down on weight yet maintains strength. This provides better power transfer and quicker and more precise front shifting performance.Hollowtech II Forged Crank ArmsA lightweight crankset not only reduces the bike's weight but decreases rotating mass to aid in acceleration. The challenge is to reduce the weight of the crank without reducing its strength and rigidity.Shimano's advanced forging technology has solved the problem through the HOLLOWTECH crank. Just like high-quality frame tubing, a hollow crank arm can provide amazing strength and rigidity at very lightweight.The Best Balance of Stiffness, Strength and WeightThe concept of Hollowtech II technology is focused on producing a superior crankset that will maximize a rider's power transfer. The rigidity of the crankset ensures pedalling efficiency while its low weight, a key element of the crankset, aids in cycling longer distances over which the rider needs to pedal more. Naturally, Shimano strove for the optimum balance between the conflicting needs of stiffness while producing a lightweight crank.The addition of Hollowtech II technology integrates the bottom bracket axle with the right crankarm for more stiffness and weight savings to achieve a high-dimensional balance. Its outboard bottom bracket bearing system provides better weight distribution and more pedalling stability, allowing for more efficient power transfer.The Shimano Dura-Ace R9200 12 Speed Chainset has been developed by pursuing the optimum balance of stiffness and rotating performance in a lightweight and beautiful crankset design.Features: Series: Dura-Ace R9200 Series Optimal balance of stiffness, strength, weight and rotational performance Hollowglide structure cuts weight yet maintains strength for better power transfer and quicker, more precise front shifting New 54-40T option to realize the most efficient drivetrain Hollowtech II crank arms for strength at a low weight Recommended Bottom Bracket: Press-Fit: SM-BB92-41B; Threaded: BB-R9100 Q-Factor: 148mm Drivetrain Rear Speeds: 12-Speed Chainline: 44.5mm Weight: 714g (54-40T); 692g (52-36T); 685g (50-34T)A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.
Shimano Dura-Ace R9200 12 Speed ChainsetThe Dura-Ace R9200 12 Speed Chainset from Shimano provides the optimum balance of strength and rigidity at a low weight. Shimano's Hollowtech II and Hollowglide technologies provide outstanding power transfer and smooth gear shifts while it's engineered to excel specifically with the Shimano 12-Speed road groupset systems.The Dura-Ace FC-R9200 chainset is the driving force at the heart of the bicycle. This chainset ensures that no portion of your pedal stroke is wasted. With hollow arms and chainrings, weight is kept to a minimum but stiffness and shifting precision is maximized.Hollowtech II Technology for World-Class Strength at a Low WeightThe Dura-Ace FC-R9200 crank performs two vital functions: transferring your pedalling effort into the drivetrain and ensuring the fastest, most precise front shifting available. With Hollowtech II crank arms to ensure lightweight and Shimano's class-leading chainring designs, the FC-R9200 won't let you down. And the FC-R9200 12 Speed Chainset is offered in even shorter crank arm lengths to ensure there are options to fit any rider.Hollowglide Chainring TechnologyHollow technology on the outer chainring. The Hollowglide construction ensures high rigidity while its hollow structure cuts down on weight yet maintains strength. This provides better power transfer and quicker and more precise front shifting performance.Hollowtech II Forged Crank ArmsA lightweight crankset not only reduces the bike's weight but decreases rotating mass to aid in acceleration. The challenge is to reduce the weight of the crank without reducing its strength and rigidity.Shimano's advanced forging technology has solved the problem through the HOLLOWTECH crank. Just like high-quality frame tubing, a hollow crank arm can provide amazing strength and rigidity at very lightweight.The Best Balance of Stiffness, Strength and WeightThe concept of Hollowtech II technology is focused on producing a superior crankset that will maximize a rider's power transfer. The rigidity of the crankset ensures pedalling efficiency while its low weight, a key element of the crankset, aids in cycling longer distances over which the rider needs to pedal more. Naturally, Shimano strove for the optimum balance between the conflicting needs of stiffness while producing a lightweight crank.The addition of Hollowtech II technology integrates the bottom bracket axle with the right crankarm for more stiffness and weight savings to achieve a high-dimensional balance. Its outboard bottom bracket bearing system provides better weight distribution and more pedalling stability, allowing for more efficient power transfer.The Shimano Dura-Ace R9200 12 Speed Chainset has been developed by pursuing the optimum balance of stiffness and rotating performance in a lightweight and beautiful crankset design.Features: Series: Dura-Ace R9200 Series Optimal balance of stiffness, strength, weight and rotational performance Hollowglide structure cuts weight yet maintains strength for better power transfer and quicker, more precise front shifting New 54-40T option to realize the most efficient drivetrain Hollowtech II crank arms for strength at a low weight Recommended Bottom Bracket: Press-Fit: SM-BB92-41B; Threaded: BB-R9100 Q-Factor: 148mm Drivetrain Rear Speeds: 12-Speed Chainline: 44.5mm Weight: 714g (54-40T); 692g (52-36T); 685g (50-34T)A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.
Shimano Ultegra R8100 12 Speed ChainsetThe Ultegra R8100 12 Speed Chainset from Shimano offers efficient power transfer, smooth gear shifting performance and top-quality race-ready reliability. Ideal for competitive road racing, this chainset offers the optimal balance of stiffness and strength at a low weight. Plus, it features Hollowtech II crank arms, a Hollowglide outer chainring and is compatible with most modern bottom bracket standards from Shimano.Shimano's Ultegra FC-R8100 crank maintains the same quick, precise front shifting and efficient power transfer that Shimano riders have grown accustomed to, but with even more crank arm length options. Spanning 160 to 175 mm in length, Ultegra cranks now cater to smaller riders, triathletes, and cyclists curious about shorter crank arms. An integral part of Shimano's new 12-Speed road lineup, the FC-R8100 crank builds upon Shimano's legendary front shifting and transmission efficiency. With new refinements for seamless 12-Speed shifting, the Ultegra crank is now offered in lengths from 160 to 175 mm, bringing performance and improved fit for smaller riders, triathletes, and riders with specific biomechanical requirements. Hollowglide ChainringHollow technology on the outer chainring. The Hollowglide construction ensures high rigidity while its hollow structure cuts down on weight yet maintains strength. This provides better power transfer and quicker and more precise front shifting performance. Hollowtech II Forged Crank ArmsA lightweight crankset not only reduces the bike's weight but decreases rotating mass to aid in acceleration. The challenge is to reduce the weight of the crank without reducing its strength and rigidity. Shimano's advanced forging technology has solved the problem through the HOLLOWTECH crank. Just like high-quality frame tubing, a hollow crank arm can provide amazing strength and rigidity at very lightweight. Optimised Balance of Stiffness, Strength and WeightThe concept of Hollowtech II technology is focused on producing a superior crankset that will maximize a rider's power transfer. The rigidity of the crankset ensures pedalling efficiency while its low weight, a key element of the crankset, aids in cycling longer distances over which the rider needs to pedal more. Naturally, Shimano strove for the optimum balance between the conflicting needs of stiffness while producing a lightweight crank. The addition of Hollowtech II technology integrates the bottom bracket axle with the right crankarm for more stiffness and weight savings to achieve a high-dimensional balance. Its outboard bottom bracket bearing system provides better weight distribution and more pedalling stability, allowing for more efficient power transfer. Features: Material: Hollowtech II Aluminium Series: Ultegra R8100 Series Optimal balance of stiffness, strength, weight and rotational performance HOLLOWGLIDE structure cuts weight yet maintains strength for better power transfer and quicker, more precise front shifting Recommended Bottom Bracket: Press-Fit: SM-BB72-41B; Threaded: SM-BBR60 Q-Factor: 148mm Chainline: 44.5mm Drivetrain Speeds: 12-Speed Weight: 711g (52-36T); 700g (50-34T)A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.
Shimano Ultegra R8100 12 Speed ChainsetThe Ultegra R8100 12 Speed Chainset from Shimano offers efficient power transfer, smooth gear shifting performance and top-quality race-ready reliability. Ideal for competitive road racing, this chainset offers the optimal balance of stiffness and strength at a low weight. Plus, it features Hollowtech II crank arms, a Hollowglide outer chainring and is compatible with most modern bottom bracket standards from Shimano.Shimano's Ultegra FC-R8100 crank maintains the same quick, precise front shifting and efficient power transfer that Shimano riders have grown accustomed to, but with even more crank arm length options. Spanning 160 to 175 mm in length, Ultegra cranks now cater to smaller riders, triathletes, and cyclists curious about shorter crank arms. An integral part of Shimano's new 12-Speed road lineup, the FC-R8100 crank builds upon Shimano's legendary front shifting and transmission efficiency. With new refinements for seamless 12-Speed shifting, the Ultegra crank is now offered in lengths from 160 to 175 mm, bringing performance and improved fit for smaller riders, triathletes, and riders with specific biomechanical requirements. Hollowglide ChainringHollow technology on the outer chainring. The Hollowglide construction ensures high rigidity while its hollow structure cuts down on weight yet maintains strength. This provides better power transfer and quicker and more precise front shifting performance. Hollowtech II Forged Crank ArmsA lightweight crankset not only reduces the bike's weight but decreases rotating mass to aid in acceleration. The challenge is to reduce the weight of the crank without reducing its strength and rigidity. Shimano's advanced forging technology has solved the problem through the HOLLOWTECH crank. Just like high-quality frame tubing, a hollow crank arm can provide amazing strength and rigidity at very lightweight. Optimised Balance of Stiffness, Strength and WeightThe concept of Hollowtech II technology is focused on producing a superior crankset that will maximize a rider's power transfer. The rigidity of the crankset ensures pedalling efficiency while its low weight, a key element of the crankset, aids in cycling longer distances over which the rider needs to pedal more. Naturally, Shimano strove for the optimum balance between the conflicting needs of stiffness while producing a lightweight crank. The addition of Hollowtech II technology integrates the bottom bracket axle with the right crankarm for more stiffness and weight savings to achieve a high-dimensional balance. Its outboard bottom bracket bearing system provides better weight distribution and more pedalling stability, allowing for more efficient power transfer. Features: Material: Hollowtech II Aluminium Series: Ultegra R8100 Series Optimal balance of stiffness, strength, weight and rotational performance HOLLOWGLIDE structure cuts weight yet maintains strength for better power transfer and quicker, more precise front shifting Recommended Bottom Bracket: Press-Fit: SM-BB72-41B; Threaded: SM-BBR60 Q-Factor: 148mm Chainline: 44.5mm Drivetrain Speeds: 12-Speed Weight: 711g (52-36T); 700g (50-34T)A 2-year warranty is offered with all Shimano products from Chain Reaction Cycles (3 years on Dura-Ace and XTR products).Buy Shimano Components from Chain Reaction Cycles, the World's Largest Online Bike Store.